Canberra
11.4 Wastewater collected

Supporting Information

Wastewater is treated at three wastewater treatment plants in the Canberra region, consisting of the Lower Molonglo Water Quality Control Centre (LMWQCC), Fyshwick Wastewater Treatment Plant (WWTP) and Queanbeyan WWTP. Some wastewater from Fyshwick and surrounding suburbs industrial area is treated at Fyshwick WWTP and returned to sewer for further treatment at LMWQCC. Water collected via the wastewater system also contains stormwater ingress.

Wastewater collected in the Canberra region in the 2010–11 year

Calculation

Wastewater treatment plant

2010–11 volume inflow (ML)

 

Lower Molonglo Water Quality Control Centre

35,072

add

Fyshwick Sewage Treatment Plant

1,739

add

Queanbeyan Sewage Treatment Plant

4,016

 

Measured inflow

40,827

less

Stormwater ingress

6,176

less

Discharge from Fyshwick Sewage Treatment Plant to Lower Molonglo Water Quality Control Centre

1,370

Equals

Total

33,281

Quantification Approach

Data Source

ActewAGL Hydstra database.

Provided by

ActewAGL.

Method

The volume of wastewater collected was determined from measured sewer flow gauges extracted from the ActewAGL Water Data Warehouse and the QCC database, less 11.7 Stormwater ingress and less the 1,370 ML that is discharged from Fyshwick Sewage Treatment Plant back into the sewer and retreated at Lower Molonglo Water Quality Control Centre.

Assumptions, Limitations, Caveats and Approximations

  • This line item is based on the assumption that in the dry reference week, there is no net gain or loss of stormwater and/or groundwater into or out of the sewer system.
  • Only the inflow to the LMWQCC is considered. Data for Queanbeyan WWTP were not available.

Uncertainty Information

These data are calculated from measured and estimated data using broad assumptions; the uncertainty is estimated to be of the order of +/–20 %.

Comparative year

This line item was not included in the 2010 Account as retail customers of the urban water system were considered to be part of the urban water system. The supply of urban water to, and collection of wastewater from, these retail customers was considered to be a within store flow and was not included in the 2010 Account Water accounting statements. Wastewater collected was included in the urban water region note. The volume reported in this note of 34,482 ML has been included in the 2011 Account as the comparative year volume for this line item.